This invention pertains to a tube puller tool assembly adapted for use in removing tight-fitting tubes from a structure such as a tube sheet of a heat exchanger, and to a method for operation of the puller tool assembly for tube removal.
Various tube pulling devices have been developed for extracting tight-fitting tubes from tube sheets of tubular heat exchangers. Such devices generally utilize a tubular housing to be placed in abutment with a tube sheet, so that a gripping member extending therefrom is inserted into and grips a tube being extracted. For example, U.S. Pat. No. 3,507,028 to Stellatella discloses a hydraulic tube puller arranged for being placed in abutment with a tube sheet and utilizes a spring-activated externally serrated end gripping member which extends into and grips a tube to be pulled, somewhat similar to the present invention. U.S. Pat. No. 3,369,287 to Brochetti and U.S. Pat. No. 4,369,569 to Armstrong et al discloses a tube pulling apparatus utilizing expandable gripping jaws and an expansion mandrel each attached to a piston actuator. U.S. Pat. No. 4,214,362 to Beard discloses a tube gripping means having a draw bar with an enlarged head portion protruding beyond a collet and having compression springs all adapted for withdrawing tubes from a support wall. Also. U.S. Pat. No. 4,679,315 to Overbay discloses a tube plug remover which includes an enlarged expanding member sized to force multiple fingers outwardly into tight engagement with inner walls of a plug to be withdrawn from a tube. However, these known tube pulling devices have various disadvantages which have now been advantageously overcome by the tube puller tool assembly of the present invention.